Genetics

Question 1

differentiation def

Answer 1

specialization of (stem) cells

Question 2

human genome project

Answer 2

1990-2003, effort to map the entire human genome > found that all humans have virtually the same genes but unique allele combinations

Question 3

single-gene inheritance

Answer 3

traits influenced by only one pair of genes

Question 4

traits that are polygenic

Answer 4

alcoholism (genes create addictive pull), nearsightedness, schizophrenia

Question 5

factors causing genetic disorders

Answer 5

“advanced maternal age” (above 35), inherited disorders, spontaneous mutation, environment

• approx 60% of abortions in 1st trimester caused by chromosomal abnormalities

Question 6

sex linked chromosomal disorders

Answer 6

red-green color blindness (pinched X) - mental disability, physical abnormalities, emotional problems

Turner syndrome (XO) - no menstrual cycle, no 2ndary sex characteristics

Klinefelter’s Syndrome (XXY) - sterile, female body characteristics

Question 7

parental imprinting

Answer 7

same allele affects embryos differently depending on whether it comes from mom or dad

Question 8

parental imprinting example

Answer 8

chromosome 15
dad - Prader Willi = overweight, slow moving, stubborn

mom - Angelman = underweight, hyperactive, overly happy

Question 9

dominant disorders probability and examples

Answer 9

rare because people rarely live long enough to reproduce
ex:
Hungtington’s chorea & Marfan syndrome

Question 10

recessive disorder examples

Answer 10

sickle cell anemia, CF, Tay-Sachs, Phenyletonurio (PKU)

Question 11

why are recessive disorders passed on

Answer 11

sometimes because the genes are protective

ex: sickle cell anemia protects against malaria

Question 12

triple/quad screen test

Answer 12

15-20 wks, maternal blood test for chromosomal abnormalities, low risk but cannot diagnose

Question 13

ultrasound

Answer 13

low/no risk, helps estimate age of baby and gender, can identify physical abnormalities

Question 14

chorionic villus sampling (CVS)

Answer 14

9/10th wk, samples hair-like material surrounding embryo

Question 15

amniocentesis

Answer 15

16th wk, samples fetal cells from amniotic fluid

Question 16

genetic counseling

Answer 16

diagnostic and preventative for higher risk parents that have family history etc

Question 17

gene therapy

Answer 17

modifies a person’s genes to treat or cure disease

methods: 1. replacing/inactivating disease causing gene

2. introducing a new/modified gene to help treat a disease

Question 18

In Vitro Fertilization (IVF)

Answer 18

adding sperm to ova that have been surgically removed from woman’s ovary and then implanting fertilized egg into woman’s uterus; no evidence of disadvantage for babies; some legal restrictions

Question 19

who is IVF used by

Answer 19

couples w/high genetic risk, gay couples, those who struggle with infertility, older women, those who want child without partner

Question 20

monozygotic twins

Answer 20

one zygote that divides, same genotype but slight variation in pheno due to environ., change can occur right after conception due to mutations bc of separate amniotic sacs/cords

Question 21

dizygotic twins

Answer 21

2 ova fertilized by 2 separate sperm, incidence is genetic, siblings born at the same time, older women more likely to double ovulate

Question 22

methods of studying individual differences

Answer 22

comparing similarity to degree of relatedness

Question 23

behavioral genetics

Answer 23

establishes the level of heritability - measure of extent to which genes determine a particular behavior or characteristic

Question 24

concordance rate

Answer 24

% of time both members show the same characteristic, higher = greater genetic influence

Question 25

heritability estimate (H^2)

Answer 25

estimate of the proportion (%) of variation within a population that is related to genes, higher # = higher estimate of genetic influence

Question 26

problems with adoption studies

Answer 26

selective children, children with behavior problems, prenatal experiences unknown

Question 27

equal environment assumption

Answer 27

assumption that MZ twins have more shared environment whereas DZ twins more non-shared; assumption that people treat MZ more similarly, evoke similar responses from others

Question 28

shared vs non-shared environment

Answer 28

shared = similar environ/experiences non-shared = unique experiences/activities people = creators of environment

Question 29

heritability inferences determined by....

Answer 29

group data, cannot be individualized, evidence of genetic influence does not imply genetic predetermination

Question 30

epigenetics

Answer 30

study of how environmental factors affect genes and genetic expression; factors can express or silence performance of certain genes

Question 31

environmental factors (epigenetics)

Answer 31

stress, environ, sleep, trauma, disease, diet

Question 32

range of reaction

Answer 32

genotype specifies range within a phenotype is expressed, environ. can determine the way that a genotype will be expressed as a phenotype

Question 33

passive genetic-environ interaction

Answer 33

environment encourages predispositions ex: parents create home environment that matches child's tendencies

Question 34

evocative gen-env interaction

Answer 34

inherited tendencies evoke more positive stimulation ex: smiling babies evoke more positive stimulation

Question 35

active gen-env interaction

Answer 35

genetic makeups encourage "niche-picking" ex: individual selects, seeks, or builds env. compatible with their predispositions